1/2 MGM grand 4am 7 handed
Effective stacks 300

Villain is 40s Hispanic man. He seems fairly aggressive in raising pre. He had raised to 10 3 times pre in the 20 minutes hero has been at the table. No other reads, wasn't paying attention postflop in the hands he raised.

Hero is young Asian male. Raised pre to 10 in LP, one caller OOP and won with a cbet on the flop. Has not played any other hands.

Villain UTG raises to 10, hero calls CO QJo, rest fold.
Flop (23): 652r
Villain checks, hero bets 15, villain calls.
Turn (53): 4o
Villain bets 15, hero raises to 50, villain calls after ~6 seconds.
River (153): 8
Villain takes ~40 seconds and bets 75. Hero?

You can argue for a fold or 3bet pre. If flatting is a mistake, it's not a big mistake imo. Hero has position, stacks are 150bb, villain opens aggressively, and 1/2 players are terrible anyway haha.

Villain's river value range is pretty narrow here. What do you think of a river raise to 150 or 200?

I'm probably wrong here but I think, in general, bluff raising river at 1/2 doesn't work enough to be profitable in most spots, esp against a V you only have 20 mins of experience with. It would have been good if you had seen what he raised with in the other spots. Opening 3 times in 20 mins doesn't make him loose. He might have just gotten decent starting hands in a cluster.
Im not a fan of flatting QJo. Even when it hits top pair, it's a tough hand to play.
That aside, V raised preflop.
V check called flop.
V bet called turn.
V bet river.
Unless you two are in some crazy leveling war, I don't think your bluff works often. V has a real hand. Not only does he keep choosing to put money in the pot, he's making smallish bets that may be blocking bets but feel more like bets he wants you to call or raise.
Any 7 or 3 makes a straight on this board. Either V doesn't put you on that or he has a straight.
On the river, he bets half pot. Given his actions up to this point, I don't see him folding. If he's a thinking player, a 2+2 forum player, maybe he can bet/fold the river. If he's typical 1/2 player, your bluff almost never works.

In your original post, you defend calling with QJo pre flop, for a raise in position. If you're going to play the hand this way and basically try to bully most flops, having QJ doesn't matter. You can do this with any two cards. I think, over time and in most situations, even against bad players, calling raises with QJo is a leak. Eff stacks are 300, so while it's only 5% of your stack, it won't make a big hand that you can crush someone with often enough to make this add up over time.